Luxon surface conditioner

[CThomp]

Anyone ever use this on fiber cement? It's made by Sherwin Williams. My brother in law uses it on cement block and stucco houses everytime he paints. He's a pro. He swears by it. Is it necessary on fiber cement board? Or will it just make the paint hold that much better?

And also...what is the best paint for fiber cement? I'll be using Sherwin Williams paint.